I have a mesa studio pre that is starting to get really noisy (being that its almost 20 years old, has seen a ton of (ab)use and the tubes have never been touched) Just wanted to know if anyone has tried out the SPAX7 in place of the 12AX7/ECC. They're only a couple dollars more. Or if anyone has any other suggestions, im open. Def dont want valves that are $50/pc. Just not in the budget. Was going to replace them all, 4 12ax7 and a single 12AT7.